‘An army marches on its stomach’, as the old saying goes, and this has proven to be just as true for space exploration as it is for military combat, although astronauts do tend to just float around aimlessly instead of marching. A recent breakthrough by Chinese scientists made use of 3D printing technology to grow food in a micro-gravity environment, which will go some way towards ensuring that the astronauts on board the proposed Chinese Space Station won’t have to go hungry.

Lettuce might not seem like something that would be a priority for a major national space program, but an astronaut not having a proper diet could turn out to be seriously costly if this started to affect their performance. China is hoping to create a permanently staffed Space Station by 2022, and is currently in the preliminary stages of trialling the technologies required, including life support equipment and apparatus. The Tiangong-2 (Heavenly Palace) satellite, which was launched in September of last year, is being used as a test environment for these technologies. The successful cultivation of lettuce plants onboard the satellite is a major step in the right direction for the Space Station program. Not only is it a healthy food, but the lettuce plant also takes a month to cultivate, which is exactly the length of the satellite's orbit.

Astronauts Jing Haipeng and Chen Dong spent 30 days aboard the satellite's Space Lab, cultivating lettuce plants and carrying out various other experiments within the weightless atmosphere. The plant growing project started on day two of their stay. They set up a culture system consisting of 3D printed cultivation boxes, which were filled with vermiculite. Vermiculite is a highly absorbent low-density mineral, with a uniform moisture conduction. Similar to how plants are grown on Earth, this vermiculite was watered before being planted with lettuce seeds and finally covered in a plastic wrap. Artificial light was shone onto the seeds for 14 hours a day to enable photosynthesis, and the astronauts used syringes to inject air into the roots of the plants, in order to keep up the oxygen supply.

The vegetable-growing experiment proved to be a great success, and the astronauts were pleased with the results and the promise they showed for the future of the Chinese space program. The lettuce needs to be bio-tested to make sure it is safe for human consumption, before later experiments in the Space Lab will allow astronauts to eat the lettuce they grow.

3D printing is playing an increasingly large role in space exploration programs the world over, driving the development of projects in the U.S, Russia, and elsewhere. This latest Chinese success story should inspire both state organizations and private companies to continue implementing the technology in their efforts to venture beyond our planet.